The Modifiable Risk Factors Branch (MRFB) focuses on factors to reduce cancer risk in humans, including exposures to nutritional components; physical activity and energy balance; alcohol and tobacco; and infectious, physical, and chemical agents. MRFB's mission is to plan, develop, direct, coordinate, and evaluate: A comprehensive program of extramural epidemiologic research in the etiology of cancer in human populations relating to factors that may be modifiable, such as nutrition, physical activity and energy balance, infectious diseases, and physical and chemical agents; A program of extramural epidemiologic research to study differences in cancer susceptibility and risk in individuals and populations and the multiple environmental and genetic factors that jointly contribute to cancer, with the ultimate goal of elucidating the etiology of cancer; A program of extramural epidemiologic research to evaluate the association of and magnitude of cancer risk associated with biomarkers of exposure, biologically effective dose, and early damage; and Research resources, infrastructures, and consortia with a focus on modifiable risk factors to facilitate and maximize the scientific potential of cancer epidemiology research. Its mission is also to disseminate findings from the research supported by the Branch to the public, health care professionals, scientists engaged in cancer control, and the public health community.